ifplugd: fix typo introduced in previous commit

Commit b1ec31a4dd2b7bd8959bdbc6d44e2cf2b56f8363 ('ifplugd: only
install default action if not provided in skeleton') introduced a
small typo, which we fix in this commit.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/ifplugd/ifplugd.mk

@@ -27,7 +27,7 @@ define IFPLUGD_INSTALL_FIXUP
 	fi
 	if [ ! -f $(TARGET_DIR)/etc/ifplugd/ifplugd.action ]; then \
 		$(INSTALL) -D -m 0755 $(@D)/conf/ifplugd.action \
-			$(TARGET_DIR)/etc/ifplugd/ifplugd.action
+			$(TARGET_DIR)/etc/ifplugd/ifplugd.action ; \
 	fi
 	$(INSTALL) -D -m 0755 $(@D)/conf/ifplugd.init \
 		$(TARGET_DIR)/etc/init.d/S45ifplugd